1. Field of Invention
This invention relates generally to electronic warfare systems and more specifically to sensors for detection of shock waves from projectiles.
2. Discussion of Related Art
In combat zones and other locations where concealed enemies may shoot at people or vehicles, it is desirable to be able to quickly identify the origin of a projectile, such as a bullet. By determining the origin of the projectile, the location of a shooter of that projectile can be identified, and defensive measures, such as moving away from the shooter or suppressing the shooter's ability to continue shooting, can be taken.
Examples of shooter localization systems are provided in U.S. Pat. Nos. 7,126,877; 7,190,633 and 7,292,501, which are hereby incorporated by reference in their entireties. Systems as described in these patents have been constructed for mounting on Humvees and other vehicles deployed in conflict areas.
Such systems employ arrays of acoustic sensors that can detect both shock waves generated as a projectile travels through air and the muzzle blast that follows. Those shock waves and muzzle blasts propagate to the acoustics sensors, where they are detected. As a projectile passes the system, its shock wave and muzzle blast will reach different sensors in the array at different times, depending on the trajectory of the projectile. By comparing arrival times of signals received at different sensors of the array, the trajectory of a projectile may be determined. Through a series of mathematical calculations, the trajectory of the projectile may be extended back to the source of the projectile, revealing the location of the shooter who launched the projectile. It is not necessary that the muzzle blast signal be recognized, but it is helpful to the solution when it is.